Copper bowl...slightly warmer weather
Old routine get it red hot and throw it in the bucket of water. Copper then is all soft and it work hardens as you beat it. Heat it red hot again and all the inner structure is reset back to soft and you can begin stretching it again.
Another couple of passes and its curling up well, notice also the edge is getting an irritating pie crust look, i will have to do something about that!